1. Field of the Invention
This invention relates generally to the automatic processing of can-packed textile sliver strands, from sliver coiling, can-packing with coiled sliver, can-changing, sliver severing of the strand between the filled can and the coiler, to a compaction of sliver in the filled can. In particular, the invention relates to a joining in operative combination of prior art coiler and can changer with a sliver compactor of special construction which in such combination acts automatically both to sever the sliver strand and compact the sliver, such operative combination being effected by a simple and reliable control means.
2. The Prior Art
With the ever growing demand for increased productivity at every stage in the processing of staple fibers to textile goods, various proposals have been made to couple by automatic means sundry concurrent or sequential processing steps toward the goal to produce more product at less cost and waste.
Especially resistant to such coupling and thus one of the "slow" steps in processing staple fibers has been the handling of sliver between processing machines by cans, such as for example between drawing frames in first and second stage drawing, or between second stage drawing and a roving frame or an open end spinner, or between a card and a draw frame or a comber. In this, the sliver may be passed through a drafting unit and condensed, coiled by a coiler apparatus and delivered as coiled strand into a can. The art is replete with disclosure of many types of can changers which automatically, upon sensing that a can had received either a predetermined weight, volume or length of sliver strand, will move the can out from under the coiler apparatus and move an empty can thereunder whereupon the coiling process may be continued.
Ancillary to can changing, whether by either manual or automatic means, is the need to sever the ultimate portion of the sliver strand which extends from the top of the filled can to the coiler apparatus. Failure to part the strand prior to beginning to fill the next empty can results in disruption of the top coils of sliver in the filled can and the bottom coils of the next can, and often the discharge of sliver onto the floor, in all creating production delays and product waste. Means for coupling automatic can changing with sliver severing also have long been known in the art and are of widely diverse sorts, as disclosed for example by British Pat. Nos. 370,081; 888,070; 829,507; 1,014,960; and 1,236,213; and by U.S. Pat. Nos. 3,249,968; 3,382,543; 3,435,485; and 3,991,443.
The limited capacity of sliver cans combined with the very open structure of the coils of sliver strand and their high resiliency have long been recognized to be inherent qualities which are inimical to attaining the aforesaid goal, and produce severe problems in providing physical means for sliver handling which include that of use of large numbers of cans, provision of storage space for cans between uses and capital investments related to maintaining a large store of cans and their replacement. These problems have been greatly aggravated in more recent times with technological advances made in increasing production rates of the fiber and sliver processing machinery. For example, with the advent of open end yarn spinners which can spin yarn at rates of three to ten times that of ring and traveller spinning machines, and the trend in their development to enormously increased rotor speeds and thus further increases in rates of yarn production, per unit of production time the numbers of cans needed to supply sliver to such machines over those required to supply the pre-processing machines for ring spinning are from three to over ten fold. Moreover, many open end yarn spinning machines require use of cans of much smaller capacity, i.e. the cans are smaller in height or diameter or both, than those employed in the preprocessing of sliver for ring spinning. Thus, the desirability long recognized in the art of being able to pack more and yet more sliver into a can is fast becoming an economic necessity. In this, the art has suggested both means for providing a more compact layering of coils of sliver with less open space between adjacent coils and means for compacting sliver coils through compression. Sundry means have been suggested for compaction through compression, it being considered that maximum benefits can be thus obtained, such as those disclosed for example in British Pat. No. 347,448 and in U.S. Pat. Nos. 1,312,953; 1,957,241; 3,241,196; 2,780,838; and 3,233,290.
Despite recognition of all of the foregoing by the art, it has been singularly silent with respect to how one may effectively combine in automatic sequential and concurrent manner can filling, can changing, and concurrent sliver severing and compaction repetitively without disrupting the sliver and creating waste. It is to fill this void in the art that this invention is directed. Other desirable objects of the invention, their advantages and means for their attainment shall become evident through the explanations which follow.